Vitamin D: don’t worry about it

In the early 2000s, vitamin D became all the rage as a sort of cure-all. People began worrying that they weren’t getting enough of the vitamin, especially after Dr. Oz, on Good Morning America, declared that 100 million people were deficient in the vitamin. Sales of vitamin D supplements soared, as did rates of vitamin D testing. Forget testing and supplements: with some exceptions, you can rest assured that you’ve got plenty of vitamin D. 

A team from Harvard Medical School conducted the world’s largest randomized vitamin D trial that followed 26,000 healthy adults for 5.3 years. Half took supplements and half didn’t. The results showed that vitamin D did not make a dent in cancer or heart disease and did not prevent falls, improve cognitive function, reduce atrial fibrillation, change body composition, reduce migraine frequency, improve stroke outcomes, decrease age-related macular degeneration, reduce knee pain, or reduce the risk of bone fractures. Subsequent studies also showed that extra vitamin D didn’t reduce diabetes risk, respiratory infections, mortality rates, or the risk of invasive cancer.

The notion that most of us are suffering from vitamin D deficiency was based on the erroneous idea that 20 nanograms per milliliter (20 ng/ml) is the bare minimum for good bone health. That’s not true. Not only is 16 ng/ml a satisfactory level, a survey of the U.S. population revealed that most of us have levels of 20 ng/ml anyway. Nevertheless, more than 10 million vitamin D tests are still done annually in the U.S., even though these tests are not recommended by major medical organizations, such as the Endocrine Society and the National Academy of Medicine.

Vitamin D is important: it helps your body absorb and retain calcium and phosphorus, which is critical for building bone. We get our vitamin D mostly from the sun. When sunlight hits your skin, it starts a chain reaction, beginning with converting a compound in your skin into a vitamin D precursor—and proceeds from there. And you don’t need much. A 2010 study calculated that between April and October someone in Boston with 25 percent of their skin exposed would need between three and eight minutes of sunlight a day. Even if you’re not getting that much, your liver and fat cells store vitamin D for future use, which generally lasts for 10 to 12 weeks.

There are some exceptions: Because certain diseases, such as Crohn’s disease and cystic fibrosis, can cause vitamin deficiency, people with those diseases might need supplements, as might people who are hospitalized or have had gastric bypass surgery. My advice: unless you’re in a special category, don’t worry about it.

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Paxlovid treatment for Covid

Paxlovid is a drug for treating Covid. It reduces the viral spread within the body and should be taken within five days of the onset of Covid symptoms. You take it for five days. I’ve never had the disease, so have no experience with the drug, but in a recent New York Times article about Paxlovid, I learned the following:

According to a million-person study by the National Institutes of Health, high-risk patients who took Paxlovid early in their illness saw a 73 percent reduction in their risk of dying from Covid, but only 15 percent of eligible patients took it. (“High risk” patients are 65 and over and those with asthma, diabetes, obesity, or other conditions.) The researchers estimated that about 135,000 hospitalizations and 48,000 deaths could have been avoided if half of the patients eligible for the medicine took it.

Reasons for not taking the drug vary, but lack of awareness was not one of them: 80 percent of the study participants knew it was available.  Many people older than 65 don’t put themselves in the high-risk category, and many wave off the drug in the early days of the disease, when symptoms tend to be mildest, thus bypassing the chance to limit early viral growth. For some, price is a concern ($1,400 per course), although it’s free for Medicaid and Medicare patients and is covered at least partially by some private insurers.

Some doctors are reluctant to prescribe it because of the long list of medications not to be mixed with Paxlovid. Patients complain about the drug’s metallic aftertaste or worry about Paxlovid rebound. (Rebound is a condition in which, after initial recovery, you either test positive again and/or experience a return of symptoms. Nobody knows for sure how common it is, and there is no strong evidence that Paxlovid causes it— a rebound has been reported by people who took the drug and those who didn’t.) 

Of those eligible (old) people I know who got Covid, some didn’t take the drug because their doctor didn’t prescribe it or no doctor was available. Of those who took it, most found it to be helpful, but some had negative experiences, including rebound and bad side effects. Those who commented on the Times article also gave mixed reviews. If I got Covid, I’m not sure what I’d do. One hurdle for us is the closure of our local clinic. Getting medical attention is now a big bother.

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.

Expiration dates and food waste

 With one exception, I never look at food expiration dates. (The exception: fresh beans sprouts. They rot fast so I look for the newest package.) Expiration dates are essentially meaningless. Here are the facts:

• Food expiration dates (e.g., "Use by") have nothing to do with safety. They’re the manufacturer’s best estimate of when the product is at its “peak quality.” (“Sell by” date is the manufacturer’s suggestion for when the grocery store should no longer sell the product.)
• Except for baby formula, there are no federal laws regarding food date labeling.
• Labels can vary from state to state.
• Labels are not science-based and no rule or regulation requires manufacturers to divulge how they reached the dates they use. 
• Pathogens don't just materialize out of thin air after the expiration date. Tests on food six months after expiration dates found no increase in the number of microorganisms in the foods and no significant changes in chemical composition.

The president of the Institute of Food Technologists once said, “In 40 years, in eight countries, if I think of major product recalls and food poisoning outbreaks, I can’t think of one that was driven by a shelf-life issue.”

As to food waste:

• The U.S. discards nearly 40 million tons of food per year, an estimated 30%-40% of the entire U.S. food supply (219 pounds per person).
• Most uneaten food rots in landfills, where it accounts for almost 25 percent of U.S. methane emissions, a significant contributor to global warming.
• People waste about $1,300 a year on tossed food.

In 1968, treasure hunters discovered a Civil War-era steamboat at the bottom of the Missouri River. Among the items recovered were several intact cans of food. Six years later scientists opened the cans to find perfectly edible peaches, oysters, and tomatoes. The food had stayed unspoiled for over a century.

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.

Napping

I’m a napper. After lunch, I go upstairs to my office, settle in my Lay-Z-Boy recliner, read for a while, then doze for ten to twenty minutes. I’ve never considered the benefits of this practice, but sleep scientists now agree that napping can help you think more clearly, react more quickly, boost your mood, and improve your memory.

The urge to nap is governed by two physiological processes. One is called homeostatic sleep pressure, which is something that builds the longer you’re awake. The other is your circadian rhythm, which typically makes you a little sleepy in the afternoon. Experts say that the best time to nap is about six to eight hours after you wake up in the morning. That’s the point where there’s a natural circadian dip because of waning hormones that help keep us alert.   

Apparently different types of naps have different effects. Long naps—more than 30 minutes—are associated with health problems. A study of more than 3,000 Europeans who napped for more than 30 minutes were 23 percent more likely to be obese than those who didn’t nap at all. They were also more likely to have a combination of high blood pressure, high cholesterol, and other health issues. As a rule, the need for frequent naps and to regularly sleep more than an hour is a sign of illness, including Alzheimer’s.

Experts agree that the sweet spot is about 20 to 30 minutes. In a 20-minute nap, you’ll be in the lightest stages of a sleep cycle, which is restorative but easy to awaken from. A recent study with young adults found that even being in a sort of twilight zone generated more creativity and better problem-solving.

I don’t care about creativity or problem solving. I just like my afternoon nap.

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.